Spotlight

Brazil’s push towards net-zero emissions relies heavily on land-hungry renewables: biofuels, solar and wind all compete for space with globally vital ecosystems. Using Brazil-Calliope, a high-resolution, spatially explicit energy system model, we show that a cost-effective, large-scale renewable energy system is possible while fully protecting priority conservation areas. Relocating generation away from these areas raises system costs by only 0.1–4% depending on the scenario, and freeing them up for restoration could enable an additional 770 million tons of annual CO₂ sequestration. The vast majority of land conversion involved in this comes from pasture and soy plantations rather than natural vegetation, and degraded pasture lands in particular are prime candidates for re-forestation. Overall, we find that smart spatial planning can reconcile Brazil’s renewable energy transition with its stewardship of biodiversity. → Borba, de Sousa and Pfenninger (2025), One Earth.

Model-based scenarios guide energy planning and climate policy, yet the beliefs modellers themselves hold about truth and objectivity in their work have received little empirical attention. In a survey of more than 160 experts across regions and disciplines, we find some areas of agreement, but also polarisation. Views cluster into two stylised profiles, the “Positivist Modeller”, who sees models as approximating an objective reality, and the “Postpositivist Modeller”, who views model results as contingent, value-laden constructs. Since epistemic beliefs shape how modellers present findings to decision-makers, making them explicit matters for the credibility of model-based policy advice. → Bock and Pfenninger-Lee (2025), Energy Research & Social Science.

Energy system models are assumption-based representations of complex systems, making validation impractical. Post-normal science suggests instead a focus on communicating values and uncertainties. Open energy modelling can support this by breaking models into manageable parts. Collaboration on these components (whether code or data) would simplify and accelerate model development, while improving accessibility and understandability for users. → Pfenninger (2024), Progress in Energy.

Airborne wind energy (AWE) systems and floating offshore turbines could unlock wind resources that conventional turbines cannot reach. However, their techno-economic potential has so far only been studied at small scale. We integrate wind resource assessment and future cost projections for both technologies into a sector-coupled, hourly-resolved energy system model of ten North Sea countries. Onshore AWE consistently outperforms conventional onshore wind thanks to stronger and distinctively-patterned winds at 250–600 m altitude, reducing total system costs by 3–16% depending on achievable power density per ground area, which emerges as the main limiting factor, more so than device cost. Offshore, AWE behaves much like its conventional rivals and competes primarily on cost. Floating turbines have higher capacity factors because they can be farther offshore, keeping them competitive even when slightly more expensive than fixed-bottom turbines. AWE in particular could play a significant role in a climate-neutral European energy supply, potentially as early as the 2030s. → Vos, Lombardi, Joshi, Schmehl and Pfenninger (2024), Environmental Research: Energy.

We show a diversity of untold options to meet all energy demand based on renewable energy, with a complete phase-out of oil and gas imports. The results can be viewed in an interactive scenario explorer. With a marginal increase above optimal cost, the reliance of an energy self-sufficient Europe on specific solutions, like biofuels, battery storage, transmission expansion, or heat electrification, can vary from not being used at all to being key to system stability. → Pickering, Lombardi and Pfenninger (2022), Joule.